JP2016153260A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress degradation of a lead-acid battery by suppressing the charging/discharging frequency of the on-vehicle lead-acid battery.SOLUTION: Each of on-vehicle power supply devices (100, 200, 300, 400, and 500) includes power generation means (11), lead-acid batteries (14 and 31) and power storage means (16, 32, 42, and 51) capable of storing power generated by the power generation means and electrically connected in parallel, adjusting means (11 and 41) capable of adjusting voltages applied to the lead-acid batteries, first switching means (23 and 24) arranged between the power storage means and the power generation means to switch electric conduction and cutting-off between the power storage means and the power generation means, and control means (22) for controlling the adjusting means to set a voltage applied to the lead-acid battery after the first switching means conducts power between the power storage means and the power generation means equal to or higher than an open circuit voltage equivalent to the fully-charged state of the lead-acid battery.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technical field of a power supply device mounted on a vehicle.

  As this type of device, for example, a lead battery and a lithium battery are connected in parallel, a MOS-FET for switching between energization and shutoff between the generator and the lithium battery, and a relay connected between the MOS-FET and the lithium battery Has been proposed that controls the operating state of the MOS-FET and the relay and the generated voltage so that the SOC (State Of Charge) of each of the lead battery and the lithium battery is within an appropriate range. (See Patent Document 1).

JP 2011-176958 A

  When the lead battery is repeatedly charged and discharged, there is a technical problem that the lead battery may be deteriorated relatively early due to the charge and discharge. It is difficult to solve this problem with the background art described above.

  This invention is made | formed in view of the said problem, for example, and makes it a subject to provide the power supply device which can suppress deterioration of a lead battery.

  In order to solve the above problems, a first power supply device of the present invention is mounted on a vehicle, can store power generation means and power generated by the power generation means, and are electrically connected to each other in parallel. A lead battery and a power storage means, an adjustment means capable of adjusting a voltage applied to the lead battery, and a power supply between the power storage means and the power generation means. And a first switching means for switching between cutoffs, wherein the first switching means energizes between the power storage means and the power generation means, and then applies a voltage applied to the lead battery to the lead battery. Control means for controlling the adjusting means so as to be equal to or higher than an open circuit voltage (OCV) corresponding to a fully charged state of the battery is provided.

  According to the first power supply device of the present invention, the power supply device is mounted on a vehicle such as an automobile. The power supply apparatus includes a power generation unit, a lead battery, a power storage unit, an adjustment unit, a first switching unit, and a control unit.

  The power generation means is not limited to a generator such as an alternator, but may be a motor / generator (motor generator). In other words, it may mean a motor / generator as long as it can function as a power generation means.

  The lead battery and the power storage means different from the lead battery are electrically connected to each other in parallel. Here, the storage means has an open circuit voltage corresponding to the upper limit value of the appropriate SOC higher than an open circuit voltage corresponding to the fully charged state of the lead battery, and an open circuit voltage corresponding to the lower limit value of the appropriate SOC is It is configured to be lower than the open circuit voltage corresponding to the fully charged state of the lead battery. Here, “appropriate SOC” means an SOC range in which early deterioration of the power storage means can be suppressed. The power storage means is not limited to a secondary battery, and may be a capacitor such as an electric double layer capacitor.

  The adjusting means is configured to be able to adjust the voltage applied to the lead battery. The adjusting means may be capable of adjusting the voltage applied to the power storage means in addition to the voltage applied to the lead battery.

  For example, the control means including a memory, a processor, etc., opens the voltage applied to the lead battery after the first switching means is energized between the power storage means and the power generation means, corresponding to the fully charged state of the lead battery. The adjusting means is controlled so as to be equal to or higher than the circuit voltage. Here, when the voltage applied to the lead battery is equal to or higher than the open circuit voltage corresponding to the fully charged state of the lead battery, the lead battery is not discharged.

  The first switching means energizes between the power storage means and the power generation means after the engine is started for the first time after the vehicle ignition is turned on, for example.

  Here, according to the inventor's research, the following matters have been found. That is, when charge / discharge of a lead battery is repeatedly performed, a decrease in the amount of liquid that causes the electrolyte solution of the lead battery to evaporate due to heat generated by charge / discharge. For example, when a lead battery is replaced due to its life, etc., if the lead battery is replaced with a low-quality lead battery that does not satisfy the performance assumed by the vehicle manufacturer, there is a risk that the rate of decrease in the electrolyte will increase. . Then, for example, there is a risk that the electrode plate of the lead battery is deteriorated (specifically, the ear of the electrode plate terminal is thin) or gas is generated.

  In the present invention, as described above, after the power storage means and the power generation means are energized by the first switching means, the voltage applied to the lead battery by the control means is an open circuit corresponding to the fully charged state of the lead battery. The adjusting means is controlled so as to be equal to or higher than the voltage.

  As a result, after the first switching means is energized between the power storage means and the power generation means (that is, after power can be supplied from the power storage means), the lead battery is not discharged. The frequency can be suppressed. Therefore, liquid reduction of the lead battery can be suppressed, and deterioration of the lead battery can be suppressed. In addition, during driving | running | working of a vehicle, for example, improvement of a fuel consumption etc. is achieved by charging / discharging an electrical storage means suitably.

  In one aspect of the first power supply device of the present invention, the voltage applied to the lead battery after the power storage means and the power generation means are energized by the first switching means is within an appropriate SOC range of the power storage means. The voltage within the corresponding open circuit voltage range.

  According to this aspect, it is possible to prevent the lead battery from being discharged while appropriately charging and discharging the power storage means when the vehicle is traveling.

  In another aspect of the first power supply device of the present invention, the power supply device further comprises temperature detection means for detecting a temperature of the lead battery, and the control means is configured to perform the first switching means according to the detected temperature. The voltage applied to the lead battery is within the range of 13.8V to 14.4V after the power storage means and the power generation means are energized and at the time of deceleration regeneration in which the power generation means generates power during deceleration of the vehicle. The adjusting means is controlled so as to have a voltage of

  According to this aspect, overcharge of the lead battery can be prevented, and generation of gas from the lead battery can be prevented. The control unit typically brings the voltage applied to the lead battery closer to 13.8 V as the detected temperature is higher, and the voltage applied to the lead battery as 14 is lower as the detected temperature is lower. Bring it close to 4V.

  In another aspect of the first power supply device of the present invention, the adjustment means is the power generation means or a DC / DC converter.

  According to this aspect, the voltage applied to the lead battery can be adjusted relatively easily. In particular, since the power generation means and the DC / DC converter are often mounted on an existing vehicle, this aspect can be realized without requiring a separate device or the like.

  In another aspect of the first power supply device of the present invention, the power storage means is a nickel metal hydride battery or a lithium ion battery.

  Nickel metal hydride batteries and lithium ion batteries have open circuit voltage characteristics similar to those of lead batteries, and the open circuit voltage corresponding to the upper limit of the appropriate SOC is fully charged. Higher than the open circuit voltage corresponding to. For this reason, the said power supply device is realizable comparatively easily by using a nickel-hydrogen battery or a lithium ion battery as an electrical storage means.

  In order to solve the above problems, a second power supply device of the present invention is mounted on a vehicle, can store power generation means and power generated by the power generation means, and are electrically connected to each other in parallel. A lead battery and a power storage means, a first switching means disposed between the power storage means and the power generation means, for switching between energization and interruption between the power storage means and the power generation means, the lead battery and the power generation And a second switching means for switching between energization and interruption between the lead battery and the power generation means, the power storage means and the power generation means by the first switching means. And a control means for controlling the switching means so as to shut off the lead battery and the power generation means when the SOC of the lead battery is equal to or greater than a predetermined value.

  According to the second power supply device of the present invention, the power supply device mounted on the vehicle includes a power generation unit, a lead battery, a power storage unit, a first switching unit, a second switching unit, and a control unit. .

  For example, the control means comprising a memory, a processor, etc. is provided between the lead battery and the power generation means when the SOC of the lead battery is equal to or greater than a predetermined value after the first switching means is energized between the power storage means and the power generation means. The second switching means is controlled so as to shut off.

  In the first power supply device of the present invention described above, in order to prevent the lead battery from being discharged after the power storage means and the power generation means are energized by the first switching means, the voltage applied to the lead battery is the lead More than the open circuit voltage corresponding to the fully charged state of the battery. In the second power supply device of the present invention, the lead battery is electrically disconnected by the second switching means in order to prevent discharge of the lead battery.

  However, if the lead battery is simply disconnected electrically, the lead battery may be deteriorated due to, for example, sulfation. Therefore, in the present invention, on the condition that the SOC of the lead battery is equal to or higher than a predetermined value, the power storage means and the power generation means are energized by the first switching means, and then the lead battery and the power generation means are shut off by the control means. Thus, the switching means is controlled.

  The “predetermined value” according to the present invention is a value that determines whether or not the lead battery and the power generation means are shut off by the second switching means, and is previously set as a fixed value or variable according to some physical quantity or parameter. It is set as a value. Such a predetermined value is obtained by experimentally or empirically or by simulation, for example, based on the relationship between the SOC of the lead battery and the possibility of deterioration of the lead battery when left for a predetermined time. What is necessary is just to set as SOC which is hardly or in tolerance level.

  Even in the second power supply device of the present invention, since the lead battery is not discharged after the power storage means and the power generation means are energized by the first switching means, the frequency of charge and discharge of the lead battery can be suppressed. Therefore, liquid reduction of the lead battery can be suppressed, and deterioration of the lead battery can be suppressed.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a block diagram which shows the principal part of the vehicle by which the power supply device which concerns on 1st Embodiment is mounted. It is a characteristic view which shows an example of OCV characteristic of each of a lead battery and a nickel metal hydride battery. It is a flowchart which shows the process mainly implemented before an engine start in 1st Embodiment. It is a flowchart which shows the power supply control process which concerns on 1st Embodiment. It is a time chart which shows a specific example of the power supply control process which concerns on 1st Embodiment. It is a flowchart which shows the power supply control process which concerns on the modification of 1st Embodiment. It is a block diagram which shows the principal part of the vehicle by which the power supply device which concerns on 2nd Embodiment is mounted. It is a block diagram which shows the principal part of the vehicle by which the power supply device which concerns on 3rd Embodiment is mounted. It is a flowchart which shows the power supply control process which concerns on 3rd Embodiment. It is a block diagram which shows the principal part of the vehicle by which the power supply device which concerns on 4th Embodiment is mounted. It is a flowchart which shows the power supply control process which concerns on 4th Embodiment. It is a block diagram which shows the principal part of the vehicle by which the power supply device which concerns on 5th Embodiment is mounted. It is a flowchart which shows the process mainly implemented before engine starting in 5th Embodiment. It is a flowchart which shows the power supply control process which concerns on 5th Embodiment.

  An embodiment according to a power supply device of the present invention will be described with reference to the drawings.

<First Embodiment>
A first embodiment of the power supply device of the present invention will be described with reference to FIGS.

  First, the configuration of the power supply device according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a main part of a vehicle on which the power supply device according to the first embodiment is mounted.

  In FIG. 1, the power supply device 100 is mounted on a vehicle (not shown) including an engine 21. The power supply device 100 includes an alternator 11 configured to be able to generate power using the driving force of the engine 21, a 12 V lead battery 14, a 12 V nickel metal hydride battery 16, and an ECU (Electronic Control Unit) 22. And is configured. In this embodiment, a part of the functions of the ECU 22 for various electronic controls of the vehicle is used as a part of the power supply device 100.

  As shown in FIG. 1, the lead battery 14, the nickel metal hydride battery 16, and the alternator 11 are electrically connected to each other in parallel. Relay switches 23 and 24 are disposed between the lead battery 14 and the nickel metal hydride battery 16. Each of the relay switches 23 and 24 is controlled by the ECU 22. The lead battery 14 is provided with a temperature sensor 25 that detects the temperature of the lead battery 14.

  A starter motor 12 and auxiliary machines 13 and 15 provided in the vehicle are electrically connected to the power supply device 100. In this embodiment, the drive voltage of the starter motor 12, the auxiliary machines 13 and 14, and the ECU 22 is 12V.

  The starter motor 12 may be realized by the alternator 11. That is, the alternator 11 may be an alternator that also serves as a starter motor. The auxiliary machines 13 and 14 are not limited to one auxiliary machine, but may be an auxiliary machine group including a plurality of auxiliary machines.

  Next, the OCV characteristics of each of the lead battery 14 and the nickel metal hydride battery 16 will be described with reference to FIG. FIG. 2 is a characteristic diagram showing an example of OCV characteristics of each of a lead battery and a nickel metal hydride battery.

  In FIG. 2, the appropriate SOC range of the nickel metal hydride battery 16 is 30% to 70%. When the SOC of the nickel metal hydride battery 16 is 30%, the OCV of the nickel metal hydride battery 16 is 12V. When the SOC of the nickel metal hydride battery 16 is 70%, the OCV of the nickel metal hydride battery 16 is 14.4V.

  The appropriate SOC range of the lead battery 14 is, for example, 90% to 100%. When the SOC of the lead battery 14 is 100% (that is, fully charged), the OCV of the lead battery 14 is 13V.

  According to the inventor's research, the following matters have been found. That is, in so-called conventional vehicles, regeneration control is often performed using a lead battery. When regenerative control is performed, the frequency of charge and discharge of the lead battery becomes relatively high, and the electrolyte solution of the lead battery easily evaporates due to the heat generated by the charge and discharge. For example, when a lead battery is replaced due to its life, etc., if the battery is replaced with a low-quality lead battery that does not satisfy the performance assumed by the vehicle manufacturer, the rate of decrease in the electrolyte caused by regenerative control, etc. May be faster. Then, for example, the electrode plate of the lead battery may be deteriorated (specifically, the ear of the electrode plate terminal) or gas may be generated. As a result, it becomes difficult to actively adopt a regenerative control function that leads to an improvement in fuel efficiency in a vehicle that is targeted for an area (for example, an emerging country) that may be replaced with a low-quality lead battery.

  Therefore, in the power supply device 100 according to the present embodiment, after the relay switches 23 and 24 are turned on, the applied voltage of the lead battery 14 is equal to or higher than the OCV of the lead battery 14 corresponding to the fully charged state of the lead battery 14. Is done. However, if the applied voltage of the lead battery 14 is too high, an overcharged state may occur and gas may be generated from the lead battery 14.

  For this reason, in this embodiment, the applied voltage of the lead battery 14 after the relay switches 23 and 24 are turned on is equal to or higher than the OCV corresponding to the fully charged state of the lead battery 14, and the lead battery 14 is overcharged. The voltage range that does not result in a state. In the case of a 12 V lead battery 14, it has been found by the inventor's research that the lead battery 14 is not overcharged if it is 14.5 V or less.

  If comprised in this way, since the lead battery 14 is not discharged after the relay switches 23 and 24 are turned on, the frequency of charging / discharging of the lead battery 14 can be suppressed. It is possible to suppress the decrease of the 14 electrolyte. Note that fuel efficiency can also be improved by performing regenerative control using the nickel metal hydride battery 16.

  Next, power supply control processing according to the present embodiment will be described with reference to the flowcharts of FIGS. 3 and 4.

  In FIG. 3, when the ignition is turned off, the relay switches 23 and 24 are in an off state, and for example, a small current (that is, a dark current) is supplied from the lead battery 14 to the auxiliary machine 13 and the ECU 22 (step S1).

  The ECU 22 as a part of the power supply apparatus 100 determines whether or not there is a request for starting the engine 21 at predetermined intervals (step S2). When it is determined that there is no request for starting the engine 21 (step S2: No), the ECU 22 once ends the process and enters a standby state. On the other hand, when it is determined that there is a request for starting the engine 21 (step S2: Yes), the ECU 22 controls the starter motor 12 and the like to start the engine 21. At this time, electric power is supplied from the lead battery 14 to the starter motor 12 (step S3).

  After the engine 21 is started, the ECU 22 turns on the relay switches 23 and 24 (step S4). Thereafter, the ECU 22 executes a power supply control process shown in the flowchart of FIG.

  In FIG. 4, the ECU 22 determines whether or not the vehicle is decelerating (step S101). In addition, since various well-known aspects can be applied to the detection of the running state of the vehicle, a detailed description thereof will be omitted.

  When it is determined that the vehicle is decelerating (step S101: Yes), the ECU 22 sets the power generation voltage of the alternator 11 to 14.4 V (step S102) and controls the alternator 11 to generate power (step S102). S103). Since the generated voltage is less than 14.4 V as described later except when the vehicle is decelerated, the generated voltage is increased when the vehicle is decelerated compared to when the vehicle is not decelerated.

  Here, since the 14.4V is higher than the fully charged OCV of the lead battery 14, the lead battery 14 is charged. Moreover, since 14.4V is an OCV of the upper limit (ie, 70%) of the appropriate SOC of the nickel metal hydride battery 16, the nickel metal hydride battery 16 is not discharged at least (the nickel metal hydride battery 16 is discharged while the vehicle is running). Since there are many opportunities, the nickel metal hydride battery 16 is typically charged).

  As shown in FIG. 1, the alternator 11 and the lead battery 14 are electrically connected to each other in parallel, so that the generated voltage of the alternator 11 becomes the applied voltage of the lead battery 14.

  Next, the ECU 22 determines whether or not the traveling is finished (that is, whether or not the ignition is turned off) (step S106). When it is determined that the travel is not finished (step S106: No), the ECU 22 once ends the process and enters a standby state, and performs the process of step S101 after a predetermined period. On the other hand, when it is determined that the travel is finished (step S106: Yes), the ECU 22 turns off the relay switches 23 and 24 (step S107).

  When it is determined in the process of step S101 described above that the vehicle is not decelerating (for example, the vehicle is accelerating, traveling at a constant speed, or stopped) (step S101: No), the ECU 22 generates the generated voltage of the alternator 11. Is set to 13V (step S104), and power generation of the alternator 11 is suppressed (step S105).

  Here, “suppressing the power generation of the alternator 11” means that, depending on the SOC of the nickel metal hydride battery 16, the power generation current of the alternator 11 is cut and the power generation is stopped, or the alternator 11 is controlled to generate power. Means that. Specifically, as shown in FIG. 2, the OCV when the SOC of the nickel metal hydride battery 16 is 50% is 13V. Therefore, until the SOC of the nickel metal hydride battery 16 falls below 50%, the ECU 22 supplies power only from the nickel metal hydride battery 16 with the alternator 11 in a power generation stop state, and the SOC of the nickel metal hydride battery 16 falls below 50%. In this case, the alternator 11 is controlled so as to generate power.

  In addition, since 13V is OCV of the fully charged state of the lead battery 14, the lead battery 14 is not discharged at least. Since the generated voltage is 14.4 V when the vehicle is decelerated, the generated voltage is lower than when the vehicle is decelerated, except when the vehicle is decelerated.

  Next, a specific example of the power supply control process described above will be described with reference to the time chart of FIG. FIG. 5 shows an example of temporal variation of various physical quantities in a certain period after the engine 21 is started (after “S4” in the flowchart of FIG. 3). As for the current of the lead battery 14 (“Pb current” in FIG. 5) and the current of the nickel metal hydride battery 16 (“Ni current” in FIG. 5), the direction of the current that flows during charging is the “positive direction”.

  Until time t1 in FIG. 5, since the vehicle is decelerating, the power generation voltage of alternator 11 is 14.4 V (corresponding to “S102” and “S103” in the flowchart of FIG. 4). Therefore, both the lead battery 14 and the nickel metal hydride battery 16 are charged (see “Ni current”, “Pb current”, “Ni SOC”, and “Pb SOC” in FIG. 5).

  When the vehicle starts to accelerate at time t1 in FIG. 5, the generated voltage of the alternator 11 is reduced to 13 V (corresponding to “S104” and “S105” in the flowchart of FIG. 4).

  Here, when the SOC of the nickel metal hydride battery 16 is 50% or more, power supply to the auxiliary machines 13 and 15 and the like is performed from the nickel metal hydride battery 16. In the period from time t1 to time t2 in FIG. 5, since the SOC of the nickel metal hydride battery 16 is 50% or more, electric power is supplied from the nickel metal hydride battery 16 to the auxiliary machines 13 and 15 (see “ Ni current ", see" Ni SOC "). At this time, the generated current of the alternator 11 is cut and the power generation is stopped (see “Alternator generated current” in FIG. 5).

  When the SOC of the nickel metal hydride battery 16 becomes less than 50% at time t2 in FIG. 5, the alternator 11 gradually restarts power generation (see “alternate current generated by the alternator” in FIG. 5). It gradually decreases (see “Ni current” in FIG. 5).

  When the vehicle starts to decelerate again at time t3 in FIG. 5, the power generation voltage of the alternator 11 is increased to 14.4V.

  Thus, since the generated voltage of the alternator 11 is higher than the fully charged OCV of the lead battery 14, the lead battery 14 is not discharged.

  The “alternator 11” according to the present embodiment is an example of the “power generation unit” and the “adjustment unit” according to the present invention. The “nickel metal hydride battery 16” and the “ECU 22” according to the present embodiment are examples of the “power storage unit” and the “control unit” according to the present invention, respectively. “Relay switches 23 and 24” according to the present embodiment is an example of “first switching means” according to the present invention.

  In the present embodiment, a nickel metal hydride battery is cited as an example of the power storage means according to the present invention. However, the present invention is not limited to a nickel metal hydride battery, but an OCV range corresponding to the appropriate SOC range, such as a lithium ion battery or an electric double layer capacitor However, it is sufficient that the OCV range corresponding to the proper SOC range of the lead battery overlaps and the OCV corresponding to the upper limit of the proper SOC range is higher than the fully charged OCV of the lead battery 14.

<Modification>
A modification of the power supply device 100 according to the first embodiment will be described with reference to the flowchart of FIG.

  In the present modification, when it is determined in the process of step S101 described above that the vehicle is decelerating (step S101: Yes), the ECU 22 detects the temperature of the lead battery 14 based on a signal from the temperature sensor 25. (Step S201). In addition, since various well-known aspects are applicable to the temperature detection method of the lead battery 14, the description about the detail is omitted.

  Subsequently, the ECU 22 sets the power generation voltage of the alternator 11 to a value within the range of 13.8V to 14.4V according to the detected temperature of the lead battery 14 (step S202), so that the determined power generation voltage is obtained. The alternator 11 is controlled. Here, the ECU 22 brings the generated voltage closer to 13.8V as the temperature of the lead battery 14 is higher, and brings the generated voltage closer to 14.4V as the temperature of the lead battery 14 is lower.

  If comprised in this way, the overcharge of the lead battery 14 can be prevented suitably and generation | occurrence | production of the gas from this lead battery 14 can be prevented.

Second Embodiment
A second embodiment of the power supply device of the present invention will be described with reference to FIG. The second embodiment is the same as the first embodiment described above except that the power supply voltage is different. Therefore, in the second embodiment, the description overlapping with that of the first embodiment is omitted, and common portions on the drawing are denoted by the same reference numerals, and only fundamentally different points are described with reference to FIG. explain. FIG. 7 is a block diagram showing a main part of a vehicle equipped with the power supply device according to the second embodiment having the same concept as in FIG. 1. Note that the vehicle according to the second embodiment is assumed to be a vehicle in which a plurality of lead batteries are electrically connected in series, such as a truck.

  In FIG. 7, the power supply device 200 includes an alternator 11, a 24 V lead battery 31 (for example, configured by connecting two 12 V lead batteries electrically in series), and a 24 V nickel metal hydride battery 32. And an ECU 22. Therefore, in this embodiment, the drive voltage of the starter motor 12, the auxiliary machines 13 and 14, and the ECU 22 is 24V.

  The power control process according to the present embodiment is basically the same as the power control process according to the first embodiment described above. However, the difference is that the generated voltages in the processes of steps S102 and S104 in the flowchart of FIG. 4 are 28.8V and 26V, respectively. That is, in the process of step S102, the ECU 22 controls the alternator 11 so that the generated voltage of the alternator 11 is 28.8V. In the process of step S104, the ECU 22 controls the alternator 11 so that the generated voltage of the alternator 11 is 26V.

<Third Embodiment>
A third embodiment of the power supply device of the present invention will be described with reference to FIGS. The third embodiment is the same as the first embodiment described above except that the configuration is partially different. Accordingly, the description of the third embodiment that is the same as that of the first embodiment is omitted, and common portions in the drawing are denoted by the same reference numerals, and FIG. 8 and FIG. The description will be given with reference. FIG. 8 is a block diagram showing a main part of a vehicle equipped with the power supply device according to the third embodiment having the same concept as in FIG. 1.

  In FIG. 8, the power supply device 300 includes the alternator 11, a lead battery 14, a second battery 42 having a high voltage such as 24 V or 48 V, a DC / DC converter 41, and an ECU 22. . For example, a nickel metal hydride battery, a lithium ion battery, or an electric double layer capacitor can be applied to the second battery 42.

  The alternator 11, the starter motor 12, the auxiliary machine 13, the lead battery 14 and the ECU 22 are electrically connected to one end of the DC / DC converter 41 of the power supply apparatus 300. A second battery 42 and a high voltage auxiliary machine 43 are electrically connected to the other end of the DC / DC converter 41.

  In this embodiment, the drive voltage of the starter motor 12, the auxiliary machine 13, and the ECU 22 is 12V, and the drive voltage of the high voltage auxiliary machine 43 is a voltage higher than 12V, such as 24V, 48V, for example.

  Next, power control processing performed by the power supply apparatus 300 configured as described above will be described with reference to the flowchart of FIG.

  9, the ECU 22 determines whether or not the vehicle is decelerating (step S101) after turning on the relay switch 24 after starting the engine 21 (step S4).

  When it is determined that the vehicle is decelerating (step S101: Yes), the ECU 22 controls the alternator 11 so that the power generation voltage of the alternator 11 is maintained at 13 V (step S301), and the second battery 42. The DC / DC converter 41 is boosted so that a voltage higher than the OCV corresponding to the current SOC is applied to the second battery 42 (step S302). Thereafter, the ECU 22 performs the process of step S106 described above. Here, since 13V is an OCV in a fully charged state of the lead battery 14, the lead battery 14 is not discharged at least.

  On the other hand, when it is determined that the vehicle is not decelerating (step S101: No), the ECU 22 performs DC / DC so that electric power is supplied from the second battery 42 (that is, the second battery 42 is discharged). While stepping down the converter 41 (step S303), the power generation of the alternator 11 is suppressed (step S304). Thereafter, the ECU 22 performs the process of step S106 described above.

  At this time, the ECU 22 performs step-down control of the DC / DC converter 41 so that the applied voltage of the lead battery 14 is 13 V or higher. If comprised in this way, the lead battery 14 will not discharge at least.

  The “DC / DC converter 41” and the “relay switch 24” according to the present embodiment are other examples of the “adjusting unit” and the “first switching unit” according to the present invention, respectively.

<Fourth embodiment>
A fourth embodiment according to the power supply device of the present invention will be described with reference to FIGS. 10 and 11. The fourth embodiment is the same as the first embodiment described above except that the configuration is partially different. Accordingly, the description of the fourth embodiment that is the same as that of the first embodiment is omitted, and common portions in the drawings are denoted by the same reference numerals, and only the points that are basically different are shown in FIGS. 10 and 11. The description will be given with reference. FIG. 10 is a block diagram showing a main part of a vehicle equipped with the power supply device according to the fourth embodiment having the same concept as in FIG.

  In FIG. 10, the power supply device 400 includes the alternator 11, a lead battery 14, a high-voltage second battery 42, a DC / DC converter 41, and an ECU 22.

  The alternator 11, the second battery 42, and the high voltage auxiliary machine 43 are electrically connected to one end of the DC converter 41 of the power supply device 400. The other end of the DC / DC converter 41 is electrically connected to the starter motor 12, the auxiliary machine 13, the lead battery 14 and the ECU 22.

  In this embodiment, the drive voltage of the starter motor 12, the auxiliary machine 13, and the ECU 22 is 12V, and the drive voltage of the high voltage auxiliary machine 43 is a voltage higher than 12V, such as 24V, 48V, for example.

  Next, the power supply control process performed by the power supply apparatus 400 configured as described above will be described with reference to the flowchart of FIG.

  In FIG. 11, the ECU 22 determines whether or not the vehicle is decelerating (step S <b> 101) after turning on the relay switch 24 after starting the engine 21 (step S <b> 4).

  When it is determined that the vehicle is decelerating (step S101: Yes), the ECU 22 controls the alternator 11 so that the generated voltage of the alternator 11 is higher than the OCV corresponding to the current SOC of the second battery 42. However (step S401), the DC / DC converter 41 is stepped down so that the applied voltage of the lead battery 14 becomes 13V (step S402). Thereafter, the ECU 22 performs the process of step S106 described above. Here, since 13V is an OCV in a fully charged state of the lead battery 14, the lead battery 14 is not discharged at least.

  On the other hand, when it is determined that the vehicle is not decelerating (step S101: No), the ECU 22 causes the alternator 11 to be supplied with power from the second battery 42 (that is, so that the second battery 42 is discharged). While suppressing power generation (step S403), the DC / DC converter 41 is stepped down so that the applied voltage of the lead battery 14 becomes 13V (step S404). Thereafter, the ECU 22 performs the process of step S106 described above.

  The “relay switch 24” according to the present embodiment is another example of the “first switching means” according to the present invention.

<Fifth Embodiment>
A fifth embodiment of the power supply device of the present invention will be described with reference to FIGS. The fifth embodiment is the same as the first embodiment described above except that the configuration is partially different. Accordingly, the description of the fifth embodiment that is the same as that of the first embodiment is omitted, and common portions in the drawings are denoted by the same reference numerals, and only the points that are basically different are shown in FIGS. The description will be given with reference. FIG. 12 is a block diagram showing a main part of a vehicle equipped with the power supply device according to the fifth embodiment having the same concept as in FIG. 1.

  In FIG. 12, a power supply device 500 includes an alternator 11, a lead battery 14, a 12V second battery 51 such as a nickel metal hydride battery, a lithium ion battery, and an electric double layer capacitor, and an ECU 22. Yes.

  A relay switch SWA is disposed between the lead battery 14 and the alternator 11. A relay switch SWB is provided between the second battery 51 and the alternator 11. Each of the relay switches SWA and SWB is controlled by the ECU 22.

  The power supply device 500 is electrically connected to the starter motor 12 and the auxiliary machines 13 and 15. In this embodiment, the drive voltage of the starter motor 12, the auxiliary machines 13 and 14, and the ECU 22 is 12V.

  In the first embodiment described above, an OCV in which the generated voltage of the alternator 11 corresponds to the fully charged state of the lead battery 14 in order to suppress the charge / discharge frequency of the lead battery 14 and suppress the deterioration of the lead battery 14. In this embodiment, the charge / discharge frequency of the lead battery 14 is suppressed by electrically disconnecting the lead battery 14 with the relay switch SWA turned off.

  Here, power supply control processing according to the present embodiment will be described with reference to the flowcharts of FIGS. 13 and 14.

  In FIG. 13, when it is determined that there is a request for starting the engine 21 (step S <b> 2: Yes), the ECU 22 controls the starter motor 12 and the like to start the engine 21. At this time, electric power is supplied from the lead battery 14 to the starter motor 12 (step S3). After the engine 21 is started, the ECU 22 executes a power control process shown in the flowchart of FIG.

  In FIG. 14, the ECU 22 determines whether or not the SOC of the lead battery 14 is equal to or greater than a predetermined value (step S501). Here, the “predetermined value” may be set as, for example, an SOC that does not deteriorate the lead battery 14 due to the influence of sulfation or the like even if the lead battery 14 is left unattended during the traveling period of the vehicle (about several hours).

  When it is determined that the SOC of the lead battery 14 is less than the predetermined value (step S501: No), the ECU 22 turns on the relay switch SWA (or the on state if the relay switch SWA is already on). (Step S508). Subsequently, the ECU 22 sets the power generation voltage of the alternator 11 to 14 V, controls the alternator 11 to generate power (step S509), and charges the lead battery 14. Thereafter, the ECU 22 once ends the process and enters a standby state, and performs the process of step S501 after a predetermined period.

  On the other hand, when it is determined that the SOC of the lead battery 14 is equal to or greater than the predetermined value (step S501: Yes), the ECU 22 turns on the relay switch SWB and electrically connects the second battery 51, and then the relay switch SWA. Is turned off to electrically disconnect the lead battery 14 (step S502).

  Next, the ECU 22 determines whether or not the vehicle is decelerating (step S503).

  When it is determined that the vehicle is decelerating (step S503: Yes), the ECU 22 sets the power generation voltage of the alternator 11 to 15 V and controls the alternator 11 to generate power (step S504). Here, 15V is assumed to be a voltage equal to or higher than the OCV of the upper limit value of the appropriate SOC of the second battery 51. For this reason, at least the second battery 51 is not discharged (the second battery 51 is typically charged because there are many opportunities for the second battery 51 to discharge while the vehicle is running).

  Next, the ECU 22 determines whether or not the traveling is finished (that is, whether or not the ignition is turned off) (step S506). If it is determined that the travel is not finished (step S506: No), the ECU 22 once ends the process and enters a standby state, and performs the process of step S501 after a predetermined period.

  On the other hand, when it is determined that the travel is finished (step S506: No), the ECU 22 turns on the relay switch SWA and then turns off the relay switch SWB (step S507).

  If it is determined in step S503 described above that the vehicle is not decelerating (step S503: No), the ECU 22 sets the power generation voltage of the alternator 11 to 12 V and suppresses power generation of the alternator 11 (step S505). ).

  Particularly in the present embodiment, since the lead battery 14 is electrically disconnected, the generated voltage of the alternator 11 can be set regardless of the OCV characteristics of the lead battery 14. Therefore, the range of the generated voltage of the alternator 11 can be made wider than that in the first embodiment described above, and the fuel efficiency resulting from the regenerative control using the second battery 51 can be improved.

  “Relay switch SWB” and “relay switch SWA” according to the present embodiment are examples of “first switching means” and “second switching means” according to the present invention, respectively.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Moreover, it is included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 11 ... Alternator, 12 ... Starter motor, 13, 15 ... Auxiliary machine, 14, 31 ... Lead battery, 16, 32 ... Nickel metal hydride battery, 21 ... Engine, 22 ... ECU, 23, 24, SWA, SWB ... Relay switch, 25 ... temperature sensor, 41 ... DC / DC converter, 42, 51 ... second battery, 43 ... high voltage auxiliary machine, 100, 200, 300, 400, 500 ... power supply device

Claims (6)

A power generation means mounted on a vehicle, capable of storing electric power generated by the power generation means, and a lead battery and power storage means electrically connected in parallel with each other, and a voltage applied to the lead battery. A power supply device comprising: an adjustable adjustment unit; and a first switching unit that is disposed between the power storage unit and the power generation unit and switches between energization and cutoff between the power storage unit and the power generation unit,
After the first switching means is energized between the power storage means and the power generation means, the voltage applied to the lead battery is adjusted to be equal to or higher than the open circuit voltage corresponding to the fully charged state of the lead battery. A power supply apparatus comprising control means for controlling the means.   The voltage applied to the lead battery after the electricity storage means and the power generation means are energized by the first switching means is a voltage within an open circuit voltage range corresponding to an appropriate SOC range of the electricity storage means. The power supply device according to claim 1. A temperature detecting means for detecting the temperature of the lead battery;
According to the detected temperature, the control means is configured such that the first switching means energizes between the power storage means and the power generation means, and at the time of deceleration regeneration in which the power generation means generates power during deceleration of the vehicle. The power supply apparatus according to claim 1, wherein the adjustment unit is controlled so that a voltage applied to the lead battery is a voltage within a range of 13.8 V to 14.4 V.   The power supply apparatus according to claim 1, wherein the adjustment unit is the power generation unit or a DC / DC converter.   The power storage device according to claim 1, wherein the power storage unit is a nickel metal hydride battery or a lithium ion battery. A power generation means mounted on a vehicle, capable of storing electric power generated by the power generation means, and a lead battery and power storage means electrically connected in parallel with each other, and the power storage means and the power generation means A first switching unit disposed between the power storage unit and the power generation unit, and disposed between the lead battery and the power generation unit, and between the lead battery and the power generation unit. A second switching means for switching between energization and cutoff, and a power supply device comprising:
After the first switching means is energized between the power storage means and the power generation means, when the SOC of the lead battery is greater than or equal to a predetermined value, the second battery is shut off between the lead battery and the power generation means. A power supply apparatus comprising control means for controlling the switching means.

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